This invention relates in general to electrostatic discharge devices and more particularly to an arrangement for discharging electrostatic potentials during the installation of an electrical substrate to a carrier substrate.
In the past few years, the use of plug-in units for electrical components has found favor within the electronics industry. Such plug-in units generally comprise a structure upon which are mounted electrical assemblies or sub-assemblies, the structure being arranged to be plugged in a suitable socket provided on a base chassis. When so plugged the components carried by the plug-in unit are electrically connected in proper circuit relation to other electrical equipment carried by the base chassis.
However, with the development of film circuits, the need for a specialized carrier structure for housing the sub-assembly has disappeared. This is due to the smaller size of a film circuit. Compared to circuits fashioned with discrete components the film circuit is appreciably smaller and lighter. It is not uncommon to have film circuits plugged directly into larger circuit cards or other carrier substrates and in turn the larger substrate plugged into the base chassis.
At present, most installations of a film circuit to a circuit card is done as a permanent installation. Therefore, removal and replacement of a film circuit though not impossible, is a tedious and labor intensive job.
One method for installing electronic substrates to a carrier substrate is taught by applicant's co-pending U.S. patent application titled, SUBSTRATE MOUNTING DEVICE. This arrangement used guides attached to a carrier substrate, such as a conventional circuit board, to accept and terminate an electronic substrate such as a hybrid film circuit deposited on a ceramic substrate.
During the installation of the above mentioned devices a possibility exists that during handling, one substrate may assume an electrical potential greater than the other. Further, during the installation of the hybrid substrate onto the carrier substrate the possibility also exists of an electrostatic charge building-up, due to the the dissimilar materials used for the guides and the hybrid film circuit. The sudden discharge of such an electrical potential can have catastrophic consequences on the sensitive low voltage components of the hybrid and/or carrier substrate.
It therefor becomes an object of the present invention to provide an arrangement for bringing an electronic substrate to the same potential as a carrier substrate.